Abstract

Joachim H. J. R. Makoi and Patrick A. Ndakidemi

A survey of chemical soil properties was conducted on six selected irrigation schemes of the Mbulu district, northern Tanzania. The focus of the study was to establish the status of the main mineral elements important for plant growth and crop production. Soil samples were collected from different sites and were analysed for physical chemical characteristics leading to the assessment of the soil fertility status by means of these main elements. The results showed variations in fertility status in the selected sites. Based on guidelines of soil mineral elements contents established elsewhere, the results showed that soil pH and excessive sodium in the soil followed by calcium in all sites; soil organic matter in 73% and cation exchange capacity in 50% of the sites are the major soil fertility constraints to crop production in the area. Crop production was also constrained by nitrogen in 50% and phosphorous in 46% of the sites. The information from our study could be used in designing fertiliser studies to establish nutrient requirements for different crops grown in these areas.